Background Payment of research participants helps to increase recruitment for research studies, but can pose ethical dilemmas. Research ethics committees (RECs) have a centrally important role in guiding this practice, but standardisation of the ethical approval process in Ireland is lacking. Aim Our aim was to examine REC policies, experiences and concerns with respect to the payment of participants in research projects in Ireland. Method Postal survey of all RECs in Ireland. Results Response rate was 62.5% (n=50). 80% of RECs reported not to have any established policy on the payment of research subjects while 20% had refused ethics approval to studies because the investigators proposed to pay research participants. The most commonly cited concerns were the potential for inducement and undermining of voluntary consent. Conclusions There is considerable variability among RECs on the payment of research participants and a lack of clear consensus guidelines on the subject. The development of standardised guidelines on the payment of research subjects may enhance recruitment of research participants